#include <iostream>
#include <string>

using namespace std;

char base[64];
char table[256];

void init(){
	for(int i = 0; i < 26; i++)
		base[i] = 'A' + i;
	for(int i = 0; i < 26; i++)
		base[26+i] = 'a' + i;
	for(int i = 0; i < 10; i++)
		base[52+i] = '0' + i;
	base[62] = '+',base[63] = '/';

	for(int i = 0; i < 256; i++) 
		table[i] =  0xff;
	for(int i = 0; i < 64; i++) 
		table[base[i]] =  i;
	table['='] = 0;
}

string decode(string str){
	string ret;
	int i;
	for(i = 0; i < str.size();i += 4){
		ret += table[str[i]] << 2 | table[str[i + 1]] >> 4;
		if(str[i+2] != '=')
			ret += (table[str[i+1]] & 0x0f) << 4 | table[str[i+2]] >> 2;
		if(str[i+3] != '=')
			ret += table[str[i+2]] << 6 | table[str[i+3]];
	}
	return ret;
}

int main(){
	init();
	cout<<int(table[0])<<endl;

	string str;
	cin>>str;
	cout<<decode(str)<<endl;
	return 0;
}
